Flexure mounted moving mirror to reduce vibration noise

Abstract

A novel means of provided a hybrid flexure mounted moving mirror component in an interferometer is introduced herein. In particular, a linear bearing in combination with a novel flexure mounting having novel tilt and velocity control of the moving optical component is provided. Such an arrangement enables correction of the errors at the mirror itself while also solving the problem of isolating vibration and noise caused by the imperfections in the bearing surfaces used in many conventional interferometers. Using such a coupled flexure mounting of the present invention, in addition to the above benefits, also enhances velocity control because the resultant low mass of the moving mirror assembly enables the systems disclosed herein to respond faster than conventional mirror velocity controlled interferometer instruments and with a lower velocity error so as to provide a more stable and lower noise spectra from the analytical instrument.

The invention claimed is: 
     
       1. A dynamic hybrid moving mirror interferometer, comprising:
 a beam splitter for receiving a beam of radiation from a source so as to provide a first and a second portioned beam; 
 a first reflector configured to receive and return said first portioned beam of said source along a first optical path length; 
 a resilient member directly coupled about the periphery of a second reflector and coupled to a support structure, wherein said resiliently mounted second reflector is configured to receive and return said second portioned beam of said source along a second optical path length; 
 a plurality of first motors coupled to a predetermined surface of said second reflector and configured to drive short stroke linear movement and, optionally, tilting movements about configured X and Y axes of said resiliently mounted reflector; 
 a second motor coupled to said support structure and configured to drive long stroke linear movement of said resiliently mounted reflector; and 
 a control system configured to provide a feedback controlled velocity control signal, said velocity control signal applied to both said plurality of first motors and to said second motor to provide short stroke velocity and position control of said resiliently mounted reflector via said velocity control signal and, optionally, tilt control about said configured X and Y axes, in addition to long stroke velocity and position control of said resiliently mounted reflector via said velocity control signal, so as to provide an interrogating interferogram of the input source beam radiation at a configured exit of said interferometer. 
 
     
     
       2. The dynamic hybrid moving mirror interferometer of  claim 1 , wherein said resilient member is designed to provide for about +/−1 millimeter of linear displacement and is further configured to provide a retarding force resultant from said about +/−1 millimeter of linear displacement. 
     
     
       3. The dynamic hybrid moving mirror interferometer of  claim 2 , wherein said resilient member provides isolation of high frequency vibrations in the range of about 50 up to about 5000 HZ. 
     
     
       4. The dynamic hybrid moving mirror interferometer of  claim 2 , wherein said resilient member comprises at least one material selected from: fabric, polymers, plastics, Mylar, metals, and paper. 
     
     
       5. The dynamic hybrid moving mirror interferometer of  claim 1 , wherein said plurality of first motors comprises a plurality of permanent magnets coupled to said predetermined surface of said second reflector, wherein applied feedback controlled magnetic fields selectively attract or repel one or more of said coupled permanent magnets in order to provide linear and, optionally, tilt movements of said resiliently mounted reflector. 
     
     
       6. The dynamic hybrid moving mirror interferometer of  claim 5 , wherein said control system is configured to enable said applied feedback controlled magnetic fields to provide for desired tilts in an X and/or Y Axis of said resiliently mounted reflector in the range of up to about 10,000 arc seconds. 
     
     
       7. The dynamic hybrid moving mirror interferometer of  claim 1 , wherein said velocity control signal is applied to said second motor to move an entire assembly that includes said resiliently mounted reflector and said support structure in a desired direction and wherein said velocity control signal is also applied to said plurality of first motors to provide one or more predetermined forces to accelerate said resiliently mounted reflector in the same said desired direction so as to accelerate together and minimize the flexed movement of said resiliently mounted reflector. 
     
     
       8. The dynamic hybrid moving mirror interferometer of  claim 7 , wherein said resiliently mounted reflector accelerates faster with respect to the remainder of said entire assembly. 
     
     
       9. The dynamic hybrid moving mirror interferometer of  claim 7 , wherein said velocity control signal is sent through a high pass filter prior to being applied to said plurality of first motors. 
     
     
       10. The dynamic hybrid moving mirror interferometer of  claim 1 , wherein vibrations are isolated in the system of said interferometer in the frequency range from about 1 Hz to greater than about 10,000 Hz.